In recent years, a photovoltaic cell that receives sunlight to generate power is becoming widely used among power consumers. Along with the wide use of the photovoltaic cell, a grid interconnection apparatus (so-called power conditioner) that interconnects the photovoltaic cell to a commercial power grid (hereinafter, “grid”) to supply power to a load is also becoming widely used.
The grid interconnection apparatus has a grid interconnection relay for performing off-line of the photovoltaic cell from the grid (see Patent Literature 1, for example).